//
// Commands are invoked from three places — a sidebar section, the Extensions
// menu, and notifications — and each passes something different. These helpers
// normalise that into "the node the user meant" and "the repository it is in".
//

const ui = require("../ui.js");

let registry = { store: null, treeViews: [] };

function configure(store, treeViews) {
    registry = { store: store, treeViews: treeViews };
}

/** Unwraps a TreeView, a node, or nothing at all into a node. */
function selectedNode(argument) {
    if (argument && Array.isArray(argument.selection)) {
        return argument.selection[0] || null;
    }
    if (argument && argument.kind) return argument;

    // Menu and palette invocations carry no argument; fall back to whichever
    // visible section currently has a selection.
    for (const view of registry.treeViews) {
        if (view.visible && view.selection && view.selection.length) return view.selection[0];
    }
    return null;
}

function repoOf(node) {
    if (!node) return null;
    if (node.repo) return node.repo;
    if (node.data && node.data.repoKey) return registry.store.repoFor(node.data.repoKey);
    return null;
}

/**
 * Resolves the repository to act on: the selected node's, the only discovered
 * one, or whichever the user picks.
 */
async function resolveRepo(argument, { prompt = "Choose a repository" } = {}) {
    const node = selectedNode(argument);
    const fromNode = repoOf(node);
    if (fromNode) return fromNode;

    const repos = registry.store.repos;
    if (!repos.length) {
        ui.warn("No Gitea repositories are available yet.");
        return null;
    }
    if (repos.length === 1) return repos[0];

    return await ui.choose(repos, {
        placeholder: prompt,
        label: (repo) => `${repo.fullName} — ${repo.baseUrl.replace(/^https?:\/\//, "")}`,
    });
}

/** Walks up from `node` to the nearest ancestor of the given kind. */
function ancestorOfKind(node, kind) {
    let current = node;
    while (current) {
        if (current.kind === kind) return current;
        current = current.parent;
    }
    return null;
}

/** Finds the pull request a node belongs to, looking at the node and its parents. */
function pullRequestFor(node) {
    let current = node;
    while (current) {
        if (current.data && current.data.pull) return current.data.pull;
        if (current.kind === "pr" && current.data && current.data.pull) return current.data.pull;
        current = current.parent;
    }
    return null;
}

function runFor(node) {
    let current = node;
    while (current) {
        if (current.data && current.data.run) return current.data.run;
        current = current.parent;
    }
    return null;
}

exports.configure = configure;
exports.selectedNode = selectedNode;
exports.repoOf = repoOf;
exports.resolveRepo = resolveRepo;
exports.ancestorOfKind = ancestorOfKind;
exports.pullRequestFor = pullRequestFor;
exports.runFor = runFor;
exports.store = () => registry.store;